Process for reconditioning spinnerets



April 26, 1938. l G. sPAANBRoEK 2,115,402

PROCESS FOR RECONDITIONING SPINNERETS Filed June 11, 1936 4 Sheets-Sheet l @w my? I April 26, 1938- G. SPAANBROEK 'l 2,1 15,402

PROCESS FOR RECONDITIONING SPINNERETS Filed June 11, 1956 Y 4 sheets-sheet 2 Filed June l1, 1956 4 Sheets-Sheet` 3 April 26, 1938. G. SPAANBROEK PROCESS FOR RECONDITIONING SPINNERETS Filed June ll, 1936 4 Sheets-Sheet 4 @www Patented Apr; 26, 1938 American corporation ci' Application .lune ll, 1936, f 1:.-

f 'iClaima 'Ihis invention relates to spinnerets adapted for use in the manufacture of articial silk, and more particularly to a process for reconditioning spinnerets which have lbecome impaired by wear A normalspinneret as employed in the articial silk industry is in the form of a small cupshaped die, the base plate of' which is perforated with minute openings through 'which a cellulosic lo solution may be forced as individual line streams.

sive action of the various chemicals to` which they 'are subjected during use. For economical reasons attempts have been u made to employ spinnerets manufactured of glass, hard rubber, bakelite and the like, but spinnerets formed of these materials were found to be impracticable due to the necessity for irequent replacement as a result of br M 41 e, wear n and other impairment. It is now generally agreed that for practical working conditions spinnerets formed of the rare metals or their alloys should be employed. An alloy of platinumand gold is one which is entirely satisfactory in the manufacture of spinnerets since a spinneret manufactured from such an alloy, although quite expensive, does not corrode and has considerable durability and wear resistance and therefore do not require frequent replacement 'during the a manufacture of artificial silk.

Although the spinnerets formed of platinum and gold alloy are comparatively durable and may be maintained in use over prolonged periods Even spinnerets manufactured from Asheville, N. E., assigner to Corporation, N. C., a

l No. 84,757

pective diameters thereof and in many instances the oriices become completely. closed. Closing of certain of the oriices results inthe production of a thread which varies from the initially formed thread and it is therefore necessary to 5 remove and replace such clogged or lpartially clogged spinnerets. 4 y y .Prior to this invention it has been ,the practice to return the impaired spinnerets to the factory for remelting and reconstruction while large numbers of newly formed spinnerets are maintained at the point of manufacture of the artiiicial silk for replacement. Even in a relatively small artiicial silk plant many thousands of spinning points are operated at one time. A

spinneret is in use at each spinning point and. many thousands of additional spinnerets must be kept in stock for replacement. -It is therefore apparent that the maintenance of many thousands of spinnerets formed of precious metm al alloys constitutes a material investment. l

The past practice involving the reconstruction of impairedspinnerets was thought to be necessary because of the fragile character of the spinnerets and the fact that the openings therein are so minute. Reconstruction was considered essential in order that the spinnerets have the exact precision required in the production of high grade artiiicial silk.

This invention has as an object the provision process of/` reconditioning spinnerets which acd0 r curateiy desi when defects in the spinneret, f

which are not normally determinable, have been eliminated.

Other objects and advantages of this invention will be apparent from the following detailed i description when consideredv in connection with theaccompanying drawings wherein:

Figure 1 illustrates a ow sheet designating the various steps of the process of this invention for reconditioning spinnerets;

Figure 2 illustrates a schematic view of a press for reshaping impaired or damaged spinnerets; l n Figure 3 is a view of a. machine for repunching, cleaning and truing the openings in spinnerets after the reshaping of the same in the press of Figure 2;

Figure 4 is a schematic View of an electroplating assembly in which the spinnerets are electroplated subsequent to the operations performed with the mechanisms illustrated in Figures 2 and 3;

Figure 5 is a cross-sectional view taken on lines 5-5 of Figure 4;

Figure 6 is a top plan view of face-polishing mechanism;

Figure 7 is a side elevational view of the polishing machine shown in Figure 6;

Figure 8 is a perspective view of a typical spinneret;

` Figure 9 is a diagrammatic view on an enlarged scale indicating the structure presented by plating the base of the spinneret;

Figure 10 is a corresponding view showing the appearance upon completion of the polishing operation; and

A Figure 11 is a corresponding view showing the appearance upon completion of the process.

In referring to the drawings indetail, reference irst will be had to the flow sheet of Figure 1. As indicated, the spinnerets to be reconditioned must b'e selected since if the openings therein have become enlarged or badly damaged, they are not readily subject to reconditioning. The impaired spinnerets primarily intended to be reconditioned in' accordance with this process are those which have been bent or distorted, those in which some of the openings have been closed by incrustations, and/orthose spinnerets which have surface defects in the form of scratches and the like. The impaired spinnerets selected for reconditioning are now subjected to the second operation during which they are straightened or reshaped so that the spinnerets are formed into their original contour. f y

The reshaped spinnerets are next subjected to 'the third operation which involves the repunching of the original Vopenings to remove incrustations and'to cause the openings each to be of substantially its original diameter. After the spinnerets have been repunched they are sub.

a spinneret iected to an electro-plating operation in which a deposit, preferably of a color contrasting to the material from which they are formed, is deposited over their outer surfaces and within all minute openings thereof. The metal deposited upon the walls of the minute openings should extend along said walls for a substantial distance, Iat least to the extent of covering the opening Walls adjacent the exterior` surface of the base. The plated spinnerets are then subjected to a grinding and polishing operation in which the outer surface of the base is polished until the electro-deposit is removed. The polished spinnerets are then inspected and if it is found that scratched or scored spaces still exist on the surface, such being readily visible because of the existence of the electro-deposit of different color Within the scratched or scored spaces, the spinnerets are further polished. When, upon inspection, they are found to bev substantially free of' any of the electro-deposit on the exterior surface, the spinnerets are placed in an acid bath, thereby chemically effecting the removal of the electro-deposit from within the openings. The latter operation results in the existence of a sharp, srrlooth edge surrounding the openings at the exterior surface of the spinnerets. The purpose'of utilizing each of the steps referred to will be more fully discussed as these steps are hereinafter discussed in detail.

Selection of spinnerets for reconditioning During the course of operation of numerous spinning points it becomes essential from time to time to replace certain of the spinnerets due to impairment as a result of scratching, bending and the plugging of the openings thereof by incrustations, These spinnerets are carefully collected and examined to determine whether the openings are unduly enlarged and whether the spinnerets are impaired otherwise than by scratches, plugged openings and general distortion. The spinnerets which are generally distorted, scratched and/or have plugged openings are then collected and conveyed to the location of the reshaping press.

Reshaping the spinneret 'Ihe selected spinnerets are reshaped on the press illustrated in Figure 2 which press is formed with a supporting frame I which contains a fixed female die member I2. The female die member is formed with a vertical bore accommodating a vertically slidable plungerv I3. Plunger I3 is resiliently supported by coil spring I4, and its upper end I acts as a base plate for female die I2. Male ldie member I6 is suspended above said female die and is adapted for coaxial downward movement thereinto effected by means of a foot pedal or other suitable pressure-applying device (not shown). Fast on male die 'I6 is a sheath l'l having upwardly extending arms I8 for operative connection with said pressure-applying device, the male die I6 being suspended by means of retractile spring I9 from guide column 20.

The spinneret 2| to be straightened is placed within the female die member I2 in position to rest upon the upper end I5 of plunger I3. Spring vit oiers suficient resistance to the downward force of male die i6 to allow proper reshaping of the spinneret. Upon each downward movement of male die I 6, annular flange 23 of spinneret 2l engages the upper edge of the female die so as to be attened thereon and straightened by compression between the female die and the lower ksurfacelof sheath il.

From the foregoing it will be observed that the face of the spinneret is straightened so as to be perfectly reformed between the cooperating surfaces of male die i6 and plunger I3, upon operation of the arms i8 to cause downward movement of the sheath I'I. Said downward movement in the normal course of operation,vis substantially `scribedwill produce accurate reshaping as a consequence of a single continuous operation, it will be understood that because the female die mem. ber forms a closely-fitting nest for the spinneret,

)successive operations may be safely imposed upon the same spinneret if necessary in order to bring about a completely satisfactory reshaping operation. Upon proper reshaping of the spinneret, the male die I6 ispermitted to be retracted into the die column 20 whereby the die member I6 clears die member I2 to permitrel J means of a hand wheel 28, punching needle 29 moval of the reshaped spinneret. After visualinspection to determine thequality of reshaping, the spinneret is conveyed to the repunching device.

Repunching the orifices vof the spinnerets The reshaped spinneret 2l is placed upon an anvil 24 of a punching device shown in Figure 3. Anvil 24 corresponds in conformation withthe spinneret in order to permit holding the spinneret stationary except that its height is less in order to allow ample clearance between the'top of anvil and the face of the spinneret for dressing or repunching orifices 26 therein. By rotating a turn table 21 supporting the anvil 25 by in a housing 3l andmaintained normally in its` uppermost position by means of la spring 32 within said housing. In its uppermost position upper -end 33 of plunger 30 is in contact with lever 36 which rotates on iixed pin 35. The lever 3i, in turn, is actuated by means of a shaft 36 which may be pushed upwardly by any suitable means (not shown). Housing 3l is maintained on a vertical support 31 fixed to the bed 38 of the punching device.

In order to provide exact inspection for determining proper alignment ofthe punching needle 29 with the spinneret orifices to beredressed, aVlow-power binocular microscope Sil is mounted on the bed 38 and disposed for convenient focusing with reference to the point of application of the punching needle. In the operation of the repunching device it will be obvious that by inverting the spinneret over the anvil the face of the spinneret will be positioned in a plane perpendicular to the axis of the punching needle. By rotating the anvil, theorices of the spinneret may be brought successively in axial alignment with the punching needle and, after focusing, dressed by successive operations of the control shaft 36. All incrustationshaving been removed thereby, and all of the oriiices having received requisite redressing by the punching device and thereby restored to their original lament-forming capacity, the spinneret is removed/from the anvil and provided with a metallic inspection cdating.

Electroplating Having been reshaped and the orices rebored to exactitude, the essential smoothness of the Y outer surface of the spinneret and the sharpness of the edges of the oriiices walls are yrestored by polishing. Howevenin order to limit the polishing eiect to the outer surface and to protect the vwalls of the orlnces, the outer surface of the spinneret is provided with a plating of suitable metal. A desirable characteristic of the electrodeposit is that it must possess a color which will contrast withthe color of the spinneret in order to be readily visually distinguishable therefrom.

Referring to Figures 4 and 5, an electroplating apparatus is diagrammatically shown. The. ap-

paratus includes a tank or container 41, the walls 'and bottom of which are of any suitable insulating material such as glass, bakelite and the like.l A suitable electrolyte 48, such as copper-sulphate solution, which may be used very satisfactorily Vin connection with a spinneret made of an alloy of platinumand gold. is placed therein. Should the electroplating ofA a 4gold spinneret be carried out in accordance with this invention, an electrolyte such as nickel-sulphate solution may be used. The purpose of the specific selection of an electrolyte will be hereinafter more fully discussed.

The apparatus includes a pair of parallel supporting bars 49 of conductive material which extend from end to end of the tank, resting in suitable recesses 50 formed therein. One of the bars 49 supports a copper plate 5i which is suspended in the electrolyte and acts as the anode. The other bar 49 supports a horizontal perforated copper tray 52 on which the spinneret, or a group thereof, is positioned, the spinneret acting as a cathode. 53 of the tray are closely spaced in order to provide free communication for the electrolyte to all surfaces of the spinneret. The tank 41 has a cover plate 5B having a central aperture 55 provided with a hermetically sealed cap 56'through which electrical connections 5l for the bars Q9 are led to any source of power (not shown) The cap 56 also includes a vacuum pump 58 driven Aby any source of power (not shown) which in for/instance, during the initial stages of electroplating the air is exhausted for a short time and thereafter atmospheric pressure'is restored. This permits the free circulation and penetration of the electrolyte throughsaid orifices in order to effect a deposition of copper entirely through the interior of the openings ,and allow the edges thereofand the face of the spinnerets to be substantially covered.

The plating action is allowed to go on for a suiiicient length of time to cover all` of the worn or abraded portions of the spinnerets. The cover plate 56 closely engages the walls` of the tank Q7 and is adapted to be hermetically sealed thereto by means of a gasket 59 and spaced bolts 6l)` carryng adjustable thumb screws 6l.4 The connections 51 carried by the cover plate 54 engage holes 62 of terminals 63 in electrical Vcommunication with the ,support bars Q9 when the cover plate 54 of the tank is in position..

Upon completion of the eleetroplating operation the electrolyte current is cut off and the cover plate removed to permit extraction of the spin- -nerets. Proper plating will be found to provide the face of the spinnerets and the walls of the orifices thereof with a continuous Aplating coating presenting the appearance indicated-in Figure 9.

Polishing Having been reshaped to remove dents, bends and warpings and electroplated` in order to protect the walls ofthe redressed orifices and to provide the inspection coating, the spinnerets are polished in order to eliminate residual flaws and scratches and to otherwise restore the faces thereof. An apparatus for polishing the spinnerets is shown in Figures 6 and 7 and includes a .rigid ,framework 10 having spaced upper and lower beds II-'H interconnected by side supports l2. The apparatus polishes the spinnerets by rotating them individually, presenting them to a rapidly rotating polishing element 13 and simultaneously oscillating the spinnerets transversely of the sur- It will be understood that perforations face of the rotating polishing element. Said api paratus is drivenirorn any suitable source of power (not shown) through a'belt 14 which drives a pulley 16 fast to a central shaft 11 suitably journaled in upper and lower beds 1I. Above upper bed 1| polishing element`13 is secured to the upper end of shaft 11. Polishing element 13 con-fU sists of a circular plate 18 covered with any suitable durable polishing fabric such as Canton annel fixed to the exterior right side out, and

i dressed with a suitable polishing, medium such as chrome-oxide suspended in tallow. It will be understood that when pulley 16 is rotated circularI plate 18 will -be driven at the same rate.

Rotation of the spinnerets is obtained through worm 8| on shaft. 11 in driving engagement with worm wheel 82 fast to horizontal shaft 83. 'I'he shaft 83 is carried by suitable bearings 85 fixed on the lowerbed 1|. At one end, shaft 83 is providedV with bevel gear 86 meshing with bevel gear 81 secured to rotatable vertical shaft 83,0n which is xed sprocket wheel 80. At spaced points about the polishing element '|3 rotatable vertical shafts 88a, 88h, and 89e are disposed, journaled'in suitablebearings in the beds 1| Adjacent the lower end said shafts are provided with sprocket wheels 30a, 80h, and 80e respectively, which are interconnected bycontinuous chain 9| whereby,` it will be observed rotation of bevel gear 81 causes shafts 83a, 08h, and 88o to be driven from sprocket wheel 90.

Above the upper bed 1|, the spaced vertical shafts 83, 89a, 89h, and 89e are each provided with a spaced collar 93 for mounting a horizontal housing or arm 94 whioh'extends toward the axis of the polishing element 13. Horizontal arms 94 are bifurcated at each end and bored freely to accommodate at one end the vertical'rotating shaft 89 and at the other a spinneret shaft 96. Sprocket wheels 91, 91a, 91h, and 81e keyed to the shafts 89, 39a, 80h, and 89e are interconnected by chains 98 with sprockets |00 keyed to the spinneret shafts 96. Sprockets 91 and |00 have' spacing'hubs i 0| which maintain them in horizontal alignment during' polishing, the sprockets |80 being normally urged to alignment by expansion springs |02 retained thereon. spinneret holders |03 are secured to the lower end of the shafts 96. It will be observed that if the polishing plate 13 is rotated -at any ratev of speed the spinneret holders |03 will be driven at a'corresponding but lower rate of speed through worm 8|, wheel 02, shaft 03, bevel gears 06 and 81. vertical shaft 88, sprocket chain 8|, sprocket wheel 91, sprocket chain 08 and spinneret shafts 96.

In order to insure optimum polishing conditions and to utilize substantially the entire surface of polishing element 10, it is proposed to cause the spinneret holders to traverse a constantly changing path with respect thereto, and this is accomplished by continuously oscillating horizontal arms 94 to carry the spinneret holders ,in an arcuate path between the axis and periph- 4jecting end of each therebeneath is fitted with a pivotally connecting link |08, the opposite end of which is pivotally connected to the under side of spider arm I Il. The relationship of the oscillat- 'ing elements described is suchthat when the spider is rocked .about the shaft"l the arms 3.4

connected thereto by means of rods ami links |08 will be oscillated across the polishing element 13, the extent of said oscillation being limited by arcuate slots |06.

Rocking of the spider |04 is accomplished through power derived from the belt 14 and central shaft 11, applied through the horizontal shaft 83 which carries a bevel gear I keyed thereto on v .the end opposite bevel gear 86. The bevel gear I engages bevel gear ||2 keyed to vertical shaft ||3 supported for rotation in xed bearing lll.

lSecured on its upper extrenty the shaft M3 is provided with disk I5 having a projecting pin |1 eccentrically disposed with respect to the shaft I3. 'Ihe pin |1 rides from end to end of straight slot ||8 cut in the spider |04. It will be observed that continuous rotation ofthe shaft i|3 as driven from the shaft v11 causes rotation of disk IIS to rock the spider through movement of pin 4I |1 in opposite directions along slot H8.

Preferably the gear ||2 is larger than the gear 81 in order that there might be obtained unbalanced equilibrium of the cooperating parts described, such coaction producing, for example. driving of the polishing disk at a speed of approximately 2,000 R. P. M. while the spinneret holders are rotated at about 100 R. P. M. and oscillated approximately 40 times per minute.

` In lieu of driving the gear 2 from the shaft 83,

the shaft may 'be connected to drive onlythe gear 81, it being feasible to drive the gear ||2 directly from the main shaft 11 by connecting a suitably geared shaft between the worm 8| and the gear i i2. it will also enable the obtaining of different speed ratios between the cooperating parts as described tion the face of the spinneret will have been treated evenly.

It is, of course, intended that the apparatus might be operated at different relative s ds of the various movements in the practice of the invention and that the specic speeds and gearing ratio indicated above are not essential to the successful'practice of the invention.

'Ihe polishing action performed on the spinf nerets progressively removes the plating so that the quality of the surface may be conveniently inspected, the contrast of color between the plating and the spinneret indicating whether.

scratches, depressions, or other irregularities remain von the face thereof. When a complete surface of spinneret material is observed the polishing is complete and the spinnerets may be re- 'moved from the polisher.

Reference to Figures 9, l0 and ll illustrates the character of the spinneret with reference to polishing. Figure 9 illustrates the spinneret with a plated coating over the face, said plated coating extending inwardly along the walls of the orifices whereby to shield the repunched orices from deformation during polishing. Complete polishing results in the construction illustrated in Figure 10. by, reference to which it will be noted that the plating is entirely removed from the polished surface of the spinneret while the When this modified construction is adopted,

residual deposit of plating material remains along walls of the orices, the accuracy and sharpness thereof having been maintained.

Removing electrolytic deposits Upon the completion of the polishing .operation. the remaining electrolytic deposits may be easily removed by dipping the spinneret in a nitric acid or other suitable bath. Brief subjection of the polished spinneret to the bath results in stripping the last vestige of electrolytic deposit therefrom to present the appearance as indicated in Figure 11. 'Iherein it will be noted that the face of the spinneret has been restored exactly to its original condition, the face being free of deformations and the orifices having their original character for the eiiicient extrusion of lament.

Operation In practicing my improved process for reconditioning spinnerets, the impaired spinneret is iirst placed upon the press and straightened by means of the die pressing machine. 'I'he spinneret is then positioned on the anvil of the repunching device and the minute orifices are cleaned and/or rebored by means of the needle mechanism. In the event the orifices are slightly enlarged the possibility exists that small raised places Vwill be formed around the edges of the openings. The next step consists in electroplating the spinneret to thereby cover these said raised portions and also cover the dents and scratches on the face of the spinneret while at the same time protecting all portions thereof. The selection of the electrolyte depends upon the material of which the spinneret is manufactured and should be of such a nature that the metal deposited is of diie'rent coloration from the material of the spinneret itself. In this manner the next step of polishing is rendered more suitable, as the damaged places to be removed will become instantaneously apparent, asv the electrolytic deposit in the damaged portions will continue to be visibleuntil they have been removed.

' During the polishing operation the deposited metal will act as a protective medium for the edges of the orices and prevent the said edges from becoming` broken or in any way marred.

As the iinal stepthe polished spinneret is dipped in nitric acid to remove the copper deposit from all parts thereof. The spinneret is then ready for reinem-poration in the spinning system. No claim is made in this application to the detailed process and apparatus for electroplating the spinnerets described herein, as that subject matter is claimed in my co-pending application Serial Number 141,806, led May 10, 1937. The

spinneret polishing apparatus is claimed in another copending application Serial Number 1311,80?, also led on May 10, 193'?.

.' What I claim is:

1. A method Aof reconditioning spinnerets which comprises the steps of selecting a spinneret which has become impaired through usage,

straightening the spinneret, repunching the orlces therein, subjecting the spinneret:` to the action of an electrolyte of such character as to coat the same with a distinguishing metal, uniformly polishing all parts of the coated face of the spinneret without injuring the edges of the orifices and removing the electrolytic deposits from the orifices of the spinneret.

2. A method of reconditioning spinnerets which have become impaired through usage, comprising straightening the spinneret to restore A its original conguration, repunching its orlces distinguishing coloration to bring out obscure de.

fects, and polishing the spinneret to remove said defects-while maintaining the edges surrounding the oriices of the vspinneret intact as a result of said coating.

4. A method of reconditioning defective spinnerets which comprises the steps of electroplating thereon an inspection coating of different coloration from the material of the spinneret t0 bring out obscure defects, polishing the spinneret to remove said defects without injuring. the oriiices lthereof and dissolving out the remaining coating.

5. A method of reconditioning spinnerets which comprises the steps of selecting a spinneret which has become impaired through usage, electroplating thereon 'ametallic coating of different coloration from the material of the spinneret in order to bring out visually defects therein, polishing the spinneret to remove the defects, and subjecting the polished spinneret to a stripping bath to remove the residual deposit of platins- 4 t 6. A method of reconditioning spinnerets which comprises the steps of straightening a spinneret which has become impaired through usage, repunching its oriiices, immersing the .spinneret in an electroplating bath and coating the same-with an inspection coating to bring out defects and protect the orliices, and polishing the plated surface to remove said defects.

'1. A method of reconditioning spinnerets which includes the steps of repunching the oriioes of an impaired spinneret, electroplating thereon an inspection coating to bring out defects and protect the orifices, polishing the plated surface to remove said defects, and subjecting .the polished spinneret to a stripping bath to remove'the residual deposit. GERRIT SPAANBROEK. 

